Geolocation of Maneuvering Emitters via RF Signal Processing

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Solution Overview

Problem

Traditional RF tracking systems are unable to effectively detect and track maneuvering targets emitting RF signals, particularly those moving at high velocities or from non-stationary platforms, due to limitations in processing moving data and requiring stationary emitters.

Innovation Solution

A high-precision geolocation architecture that utilizes a distributed network of RF collectors, cooperative collection managers, and dynamic cross ambiguity function (DCAF) processing to convert RF signals to In-phase and Quadrature (I/Q) data, calculate Time Difference of Arrival (TDOA) and Frequency Difference of Arrival (FDOA) measurements, and estimate the trajectory of moving targets using GPU parallel processing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional RF tracking systems use stationary platforms or emitters, then system complexity is reduced and operation is simplified, but the ability to detect and track maneuvering targets is lost

Engineering Contradiction:

Improveability to track maneuvering targetsVSAvoidsystem complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic tracking capabilities by enabling both platforms and emitters to move freely. The system uses real-time position data from GPS receivers on mobile platforms combined with signal processing algorithms that account for platform motion, allowing maneuvering targets to be tracked without requiring stationary components. This dynamic approach resolves the contradiction by making the system adaptable to moving targets while managing complexity through software-based solutions rather than fixed infrastructure.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent introduces a signal processing intermediary layer that processes RF signals to extract target information while compensating for platform motion. This intermediary processing stage uses algorithms to separate target maneuvering from platform movement, enabling the system to track maneuvering targets without requiring the platforms themselves to be stationary, thus resolving the adaptability-complexity contradiction.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If traditional systems require stationary emitters or platforms, then measurement setup is simplified, but tracking of highly maneuvering emitters becomes impossible

Engineering Contradiction:

Improvetracking capability of maneuvering emittersVSAvoidoperation simplicity

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The system embraces dynamic operation by allowing platforms to move freely while using real-time position data and signal processing to maintain accurate target tracking. The ease of operation is maintained through automated algorithms that handle the complexity of motion compensation, allowing operators to simply deploy mobile platforms and initiate tracking without complex setup procedures.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system performs self-service by automatically compensating for platform motion and target maneuvering through onboard GPS receivers and signal processing algorithms. This self-service capability allows the system to maintain accurate tracking without requiring manual intervention or simplified stationary setups, resolving the contradiction between tracking capability and operational simplicity.

Inventive Principle:

Principle #25Self-service

3Reliability

If traditional systems collect data only from stationary platforms, then data processing is simplified, but detection of moving target data is not achieved

Engineering Contradiction:

Improvedetection accuracy of moving targetsVSAvoiddata processing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic data processing that accounts for platform motion and target maneuvering. GPS receivers on mobile platforms provide real-time position data that is integrated with RF signal processing to accurately detect and track moving targets. This dynamic processing approach improves detection reliability while managing complexity through coordinated use of navigation and RF data streams.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system merges navigation data from GPS receivers with RF signal data from mobile platforms to achieve accurate moving target detection. By combining these data streams and processing them together through integrated algorithms, the system improves detection reliability while avoiding the complexity of separate processing systems, as the merged approach leverages the complementary information from both sources.

Inventive Principle:

Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables real-time passive tracking of maneuvering targets with low-SINR signals, overcoming the limitations of traditional systems by providing accurate position and velocity data even from mobile platforms, and adapting to available computational resources.

Implementation Method 1

receiving, using radio frequency (RF) collectors communicatively coupled to the computing system, RF signals from a target object

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

determining, using the paired I/Q data of the RF collectors, one or more of time difference of arrival (TDOA) measurement data and frequency difference of arrival (FDOA) measurement data between each pair of the RF collectors

Methodology Applied

Scientific EffectTime of flight: Time of Flight

Implementation Method 3

Methodology Applied

Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentUS20240393421A1Geolocation method for detection and tracking of maneuvering emitters

Publication Date: 2024.11.28 LOCKHEED MARTIN CORP

AI summary

A method includes receiving, using radio frequency (RF) collectors, RF signals from a target object. The RF signals of target object may be converted to In-phase and Quadrature (I/Q) data. Navigation data of each RF collector may be determined and I/Q data of each of RF collectors are paired. Processing functions may be applied on paired I/Q data. Using paired I/Q data, one or more of time difference of arrival (TDOA) measurement data and frequency difference of arrival (FDOA) measurement data between each pair of the RF collectors are determined. One or more of TDOA measurement data, FDOA measurement data and navigation data of each RF collector are converted to message data. A trajectory of target object may be estimated based on confidence measure of one or more of TDOA and FDOA measurement data. Using estimated trajectory of target object for displaying on a display device of a computing device.